The contacts where the G209 memory selector cards plug in had noticeable Corrosion on some of the contacts. The cleaner I had that I found that would remove it was Goddard's silver dip. I used a small cotton tipped applicator to clean the exposed portion of the contacts and card stock to clean the portion where the card plugs in. I then used Dust-Off cleaner degreaser spray (mostly alcohol) to remove the residue and silver dip. I made sure that nothing could drip into the core stack. It seemed to clean up pretty well though I'm not sure how much of the gold is gone. I used Caig PreservIT hoping that will slow down corrosion if the base copper is exposed.

Feel free to contact me, David Gesswein djg@pdp8online.com
with any questions, comments on the web site, or if you have related equipment,
documentation, software etc. you are willing to part with. I am
interested in anything PDP-8
related, computers, peripherals used with them, DEC or third party, or
documentation.